(HP-97) Design one-shot multivibrators

[mfleming]

Thanks for the source SlideRule! Is it from volume 1 of the series? Abe Books only turns up volume 4 (1980) in quantity at a dizzying price, along with two that may be first edition (1964). I can remember browsing Electronic Design and other magazines at the library as an undergraduate looking for ideas like this one...

Looks like the original equation is
$$T = 0.32(R+0.7)C + 11.8(R^.837)$$

So the addition operator in step 34 is correct. Step 18 is RCL D as noted, and step 61 should be a decimal point rather than the subtraction operator. Here's a correction in "Teenix" format with key codes for the HP-67 (I have no HP-97, and given the price on TAS, I'm very likely never to have one ) The updated ZIP file from my previous post contains the same listing along with the program card to load into the Teenix HP-67 emulator.

Code:


001  f LBL E     32 25 15
002  STO E       33 15
003  h F3set?    35 71 03
004  h RTN       35 22
005  f GSB 2     31 22 02
006  RCL C       34 13
007  X           71
008  f GSB 1     31 22 01
009  +           61
010  STO E       33 15
011  g SCI       32 23
012  DSP 1       23 01
013  f RND       31 24
014  f FIX       31 23
015  DSP 0       23 00
016  h RTN       35 22
017  f LBL 1     31 25 01
018  RCL D       34 14
019  .           83
020  8           61
021  3           61
022  7           61
023  h YtoX      35 63
024  1           61
025  1           61
026  .           83
027  8           61
028  X           71
029  h RTN       35 22
030  f LBL 2     31 25 02
031  .           83
032  7           07
033  RCL D       34 14
034  +           61
035  .           83
036  3           03
037  2           02
038  X           71
039  h RTN       35 22
040  f LBL C     32 25 13
041  ENTER       41
042  g FRAC      32 83
043  f x=0?      31 51
044  GTO C       22 31 13
045  CLx         44
046  EEX         43
047  6           06
048  X           71
049  ENTER       41
050  f LBL C     32 25 13
051  h ROLDN     35 53
052  STO C       33 13
053  h F3set?    35 71 03
054  h RTN       35 22
055  RCL E       34 15
056  f GSB 1     31 22 01
057  -           51
058  f GSB 2     31 22 02
059  /           81
060  STO C       33 13
061  .           83
062  9           09
063  h X<->Y     35 52
064  g x<=y?     32 71
065  GTO e       22 31 15
066  f FIX       31 23
067  DSP 0       23 00
068  h RTN       35 22
069  f LBL D     32 25 14
070  STO D       33 14
071  h F3set?    35 71 03
072  GTO D       22 31 14
073  3           03
074  h STO (i)   33 24
075  1           01
076  0           00
077  STO D       33 14
078  f LBL d     32 25 14
079  f GSB 2     31 22 02
080  RCL C       34 13
081  X           71
082  f GSB 1     31 22 01
083  +           61
084  RCL E       34 15
085  h X<->Y     35 52
086  /           81
087  RCL D       34 14
088  X           71
089  STO D       33 14
090  f DSZ       31 33
091  GTO d       22 31 14
092  f LBL D     32 25 14
093  4           04
094  .           83
095  9           09
096  h X<->Y     35 52
097  g x<=y?     32 71
098  GTO e       22 31 15
099  5           05
100  0           00
101  h X<->Y     35 52
102  g x>y?      32 81
103  GTO e       22 31 15
104  DSP 1       23 01
105  h RTN       35 22

Pedro, an example would be something like this. You'd like a 100 nSec pulse from a one-shot, so you'd start with a one puff cap as a good guess and enter into the calculator

100 "E" (enter value of pulse time in nanoseconds)
1 "C" (enter value of capacitance in picoFarads)
"D" (calculate value of resistor in kiloOhms)
12.2 (displayed result)

Given that era, you were probably working with 10% resistor values (5% for military, 1% for NASA!). Values in the E12 series are

1.0 1.2 1.5 1.8 2.2 2.7 3.3 3.9 4.7 5.6 6.8 8.2 times a decade multiplier

So the best resistor value would be a 12 Kohm, 10% resistor. If on the other hand suppose you wanted a 250 ns pulse. Enter the known value T and a guess for C.

250 "E" (New pulse time, 250 ns)
1 "C" (starting value for C)
"D" (calculate resistor value)
Displays 36.1 (KOhms)

The calculated resistor value (36.1 Kohm,) doesn't fit well in the above E12 series. Try using the next two decade values for capacitance, 10pF and 100pF.

250 "E" (nSec)
10 "C" (pF)
"D"
Displays 24.2 (KOhm)

250 "E" (nSec)
100 "C" (pF)
"D"
Displays 5.6 (KOhm)

A 100pF capacitor gives a resistor value of 5.6KOhms and that is right on the nose in the E12 series.

Now imagine doing this trial and error process with a slide rule or non-programmable calculator!
~Mark